Caster



(No Model.)

S. T.'LAMB.

'GASTER.

No. 355,020. Pa tented Deo. 23, 1886.

, UNITED STATES PATENT OFFICE.

. SALEM T. LAMB, 0F NEW'AI lBA NY, INDIANA.

CAS'TER.

SPECIFICATION forming part of Letters Patent No. 355,020, dated December 28, 1886. Application filed May 13, 1884. Serial No. 131,385. (No model.)

To all whom it may concern.-

Be it known that I, SALEM T. LAMB, a citizen of the United States,and a resident of New Albany, Floyd county, Indiana, have invented certain new and useful Improvements in Gasters, of which the following is a specification.

My invention relates to that class of casters in which the pivoted frame is provided with friction-wheels that bear upon the lower face of the stationary frame; and my invent-ion consists in constructing the parts, as fully described hereinafter, so as to render the device com pact and durable, and reduce the expense of manufacture.

In the drawings, Figure 1 is a side elevation of my improved caster. Fig. 2 is a plan of the pivoted frame. Fig. 3 is an inverted plan of the caster. Fig. 4 is a side elevation showing the parts in a different position from that illustrated in Fig. 1. Fig. 5 is a rear View.

The stationary portion A of the caster is formed to correspond to the situation to which it is to be applied. In some instances it is tubular or socketed, in others it is a disk, and in others, as shown in the drawings, it is L- shaped, to constitute a bracket, the horizontal portion a of which is adapted to fit beneath the leg, standard, or platform to be supported, while the vertical portion a is arranged to fit against the side of the said part, and each part may be provided with countersunk openings for the passage of screws.

To enable me to apply the caster to the posts of bedsteads and feetof other articles without the necessity of altering the positions of said article other than to elevate the feet, I dispense with screws through the bottomplate, a, but provide the latter with a pintle, b, which relieves the screws extending through the. plate a of all strain; and to secure an annular bearing of sufficient extentfor the friction-wheels Without enlarging the dimensions of the frame beyond said bearing, and yet secure an L -shaped frame, I set the vertical portion a of the frame at a point between the pivot and the edge of the annular disk a, as shown in the drawings, and strengthen this portion by one or more vertical ribs, 8, so that the lower plate, a, is no larger than necessary to secure a bearing for the friction-wheels. At the bottom of the portion a is a hub, 0. through the center of which extends the usual pivot-pin, d, pivoting the swinging or movable frame or part B of the caster to the part A, the bearing-surfaces of both the hub and frame B being flat and preventing the said' frame B from rocking.

The frame B consists of a U shaped bracket, f, through the center of which the pin d extends, and between the arms of which rotates the usual caster-wheel, O, turning upon a pin, 6, extending through ears 9 at the forward ends of the arms, the said ears projecting downward. At the forward end of each arm are upwardlyextending parallel ears i i, through which extend pins m, each arranged upon a line radiating from the center of the pin d, the two radial lines being at right angles to each other, and upon each pin as a journal turns a friction-roller, D, which bears against the under side of the plate a, each roller traveling upon the same path or circle as the other, an annular rib, n, constituting in most instances the bearing-surface.

It will be seen that by extending the arms of the frame B to the sides of the wheel 0 and arranging the ears 2' as set forth the bearings of all the wheels are brought very close together, and the journals of the friction-rollers may be placed in a position ona level or thereaboutwith the top of the wheel 0. Iam thus enabled to use friction-rollers of comparatively large diameter, and yet bring the wheel Gvefy close to the plate a, so that there is much less leverage exerted by the movable frame upon the pind than in those cases where the friction-wheels are arranged wholly above'the wheel 0.

A. similar arrangement of friction-wheels in respect to the wheel 0 is set forth in the Letters Patent granted to me August 30, 1881, No. 246,520; but in that case the friction-rollers were supported upon pins projecting laterally from studs. This construction results in considerable strain upon the pins,which are sometimes bent, and impairs the efficiency of x the caster.

Another arrangement is shown in Patent N 0. 126,433, wherein a horizontal frame has a seat or bearing for a hub, and is provided with recesses, forming bearings for friction-rolls.

By constructing the frame B with a forked IOO support or parallel ears for each roller, arranged in close proximity to the axis of the wheel 0, I make a much more durable structure, use lighter pins for the friction-wheels, bring the wheel -bearings nearly in the same vertical plane, and reduce the cost of manufacture.

To facilitate the manufacture and avoid the necessity of coring the casting, I make the frame B with the ears 1' parallel to each other and at right angles to the upper plane, to, of the frame, and the ears 9 at right angles to the same plane, so that the pattern will readily draw from the sand on both sides.

.. If itis desirable to carry the roller 0 nearer to the plate a, the pin or journal 6 may be 10- cated at a higher point, as shown in dotted lines, Fig. 5; but I prefer in most instances the arrangement shown in the, other figures of the in the frame B to correspond in diameter only at the lowest point, enlarging the opening or reducing the pin above this point, so that the frame may tilt without binding or wear. By this means the frame B is maintained for a much longer time central with the frame A than would be possible if the lower frame should bear on and wear away thepivot.

I have found that by constructing the caster so that the lower face of the yoke f, where the frame B bears on the head of the pivot, is on a line, Z, with the journals of the frictionrollers the frame B is much less liable to bind than when the bearing of the frame on the pivot is above or below this line.

Without limiting myself to the precise construction andarrangement of parts shown, I

- claim-- 2. The bifurcated frame B, pivoted to the stationary plate of the caster, each of the arms having upwardlyextending ears 2' in close proximity to the axis of the caster-wheel, and supporting journals below the periphery of the said caster-wheel and above the axis of the same, and downwardly-projecting ears 9 under said ears 1' and forming the bearings oi the caster-wheel, substantially as described.

3; .A caster provided with the pivoted frame carrying the-caster-wheel, and with a stationary frame consisting of an L-shaped bracket having an upwardly-extending pintle, b, substantially as specified. V

4. A caster having a pivoted frame carrying the caster wheel and friction-wheels, and a stationary frame with a horizontal portion constituting a bearing for the friction-wheels, and with a vertical portion at right angles to and within the periphery of the horizontal portion, substantially as described.

5. The combination of the stationary frame having a flat bearing-surface, a pivoted frame carrying the caster and friction wheels, and having a flat surface bearing against the flat surface of the stationary frame, and also provided with an expanded opening,and a pivot secured to the stationary frame and extending through the said expanded opening, whereby the pivoted frame is prevented from straining the pivot or rocking, substantially .as described.

V 6. The combination of the stationary frame having a flat bearing-surface, the pivoted frame carrying the caster, and friction-wheels at the sides of said caster, and having a flat bearing-surface, and a oonnecting'pivot extending through an expanding opening in the pivoted frame, and having the bearing-surface of its head in the same plane as the axes of the friction-wheels, the said pivot being independent of said frictiomwheels, substantially as described.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

SALEM T. LAMB.

NVitnesses:

' W. G. DUVALL,

CHARLES E. FOSTER. 

